Collidoscope

/*

 Copyright (C) 2016  Queen Mary University of London 

 Author: Fiore Martin

 This file is part of Collidoscope.

 Collidoscope is free software: you can redistribute it and/or modify

 it under the terms of the GNU General Public License as published by

 the Free Software Foundation, either version 3 of the License, or

 (at your option) any later version.

 This program is distributed in the hope that it will be useful,

 but WITHOUT ANY WARRANTY; without even the implied warranty of

 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License

 along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "AudioEngine.h"

// app.h include not used 

#include "cinder/app/App.h"

#include "Log.h"

using namespace ci::audio;

/* Frequency ratios in the chromatic scale */

double chromaticRatios[] = { 

    1, 

    1.0594630943591, 

    1.1224620483089, 

    1.1892071150019, 

    1.2599210498937, 

    1.3348398541685, 

    1.4142135623711, 

    1.4983070768743, 

    1.5874010519653, 

    1.6817928305039, 

    1.7817974362766, 

    1.8877486253586 

};

/*

 * Calculates the ratio between the frequency of the midi note passed as argument and middle C note ( MIDI value = 60 ).

 * This is used for pitch shifting the granular synth output, according to the key pressed by the user.

 * The middle C is taken as reference in pitch in the pitch shifting of Collidoscope output.

 * That is, with the middle C the output is not pitch shifted at all and is equal in frequency to the recorder sample.

 *

 */ 

inline double calculateMidiNoteRatio( int midiNote )

{

    int distanceFromCenter = midiNote - 60; // 60 is the central midi note 

    if ( distanceFromCenter < 0 ){

        int diffAmount = -distanceFromCenter;

        int octaves = diffAmount / 12;

        int intervals = diffAmount % 12;

        return std::pow( 0.5, octaves ) / chromaticRatios[intervals];

    }

    else{

        int octaves = distanceFromCenter / 12;

        int intervals = distanceFromCenter % 12;

        return std::pow( 2, octaves ) * chromaticRatios[intervals];

    }

}

AudioEngine::AudioEngine() 

{}

AudioEngine::~AudioEngine()

{}

void AudioEngine::setup(const Config& config)

{

    for ( int i = 0; i < NUM_WAVES; i++ ){

        mCursorTriggerRingBufferPacks[i].reset( new RingBufferPack<CursorTriggerMsg>( 512 ) ); // FIXME 

    }

    /* audio context */

    auto ctx = Context::master();

    /* audio input device */

    auto inputDeviceNode = ctx->createInputDeviceNode( Device::getDefaultInput() );

    /* route the audio input, which is two channels, to one wave graph for each channel */

    for ( int chan = 0; chan < NUM_WAVES; chan++ ){

        /* one channel router */

        mInputRouterNodes[chan] = ctx->makeNode( new ChannelRouterNode( Node::Format().channels( 1 ) ) );

        /* buffer recorders */  

        mBufferRecorderNodes[chan] = ctx->makeNode( new BufferToWaveRecorderNode( config.getNumChunks(), config.getWaveLen() ) );

        /* this prevents the node from recording before record is pressed */

        mBufferRecorderNodes[chan]->setAutoEnabled( false );

        // route the input part of the audio graph. Two channels input goes into one channel route

        // and from one channel route to one channel buffer recorder 

        inputDeviceNode >> mInputRouterNodes[chan]->route( chan, 0, 1 ) >> mBufferRecorderNodes[chan];

        // create PGranular loops passing the buffer of the RecorderNode as argument to the contructor 

        // use -1 as ID as the loop corresponds to no midi note 

        mPGranularNodes[chan] = ctx->makeNode( new PGranularNode( mBufferRecorderNodes[chan]->getRecorderBuffer(), mCursorTriggerRingBufferPacks[chan]->getBuffer() ) );

        // create filter nodes 

        mLowPassFilterNodes[chan] = ctx->makeNode( new FilterLowPassNode( MonitorNode::Format().channels( 1 ) ) );

        mLowPassFilterNodes[chan]->setCutoffFreq( config.getMaxFilterCutoffFreq() );

        mLowPassFilterNodes[chan]->setQ( 0.707f );

        // create monitor nodes for oscilloscopes 

        mOutputMonitorNodes[chan] = ctx->makeNode( new MonitorNode( MonitorNode::Format().channels( 1 ) ) );

        // all output goes to the filter 

        mPGranularNodes[chan] >> mLowPassFilterNodes[chan];

        mOutputRouterNodes[chan] = ctx->makeNode( new ChannelRouterNode( Node::Format().channels( 2 ) ) );

        // filter goes to output 

        mLowPassFilterNodes[chan] >> mOutputRouterNodes[chan]->route( 0, chan, 1 ) >> ctx->getOutput();

        // what goes to output goes to oscilloscope as well

        mLowPassFilterNodes[chan] >> mOutputMonitorNodes[chan];

    }

    ctx->getOutput()->enableClipDetection( false );

    /* enable the whole audio graph */

    inputDeviceNode->enable();

    ctx->enable();

}

size_t AudioEngine::getSampleRate()

{

    return Context::master()->getSampleRate();

}

void AudioEngine::loopOn( size_t waveIdx )

{

    NoteMsg msg = makeNoteMsg( Command::LOOP_ON, 1, 1.0 );

    mPGranularNodes[waveIdx]->getNoteRingBuffer().write( &msg, 1 );

}

void AudioEngine::loopOff( size_t waveIdx )

{

    NoteMsg msg = makeNoteMsg( Command::LOOP_OFF, 0, 0.0 );

    mPGranularNodes[waveIdx]->getNoteRingBuffer().write( &msg, 1 );

}

void AudioEngine::record( size_t waveIdx )

{

    mBufferRecorderNodes[waveIdx]->start();

}

void AudioEngine::noteOn( size_t waveIdx, int midiNote )

{

    double midiAsRate = calculateMidiNoteRatio(midiNote);

    NoteMsg msg = makeNoteMsg( Command::NOTE_ON, midiNote, midiAsRate );

    mPGranularNodes[waveIdx]->getNoteRingBuffer().write( &msg, 1 );

}

void AudioEngine::noteOff( size_t waveIdx, int midiNote )

{

    NoteMsg msg = makeNoteMsg( Command::NOTE_OFF, midiNote, 0.0 );

    mPGranularNodes[waveIdx]->getNoteRingBuffer().write( &msg, 1 );

}

void AudioEngine::setSelectionSize( size_t waveIdx, size_t size )

{

    mPGranularNodes[waveIdx]->setSelectionSize( size );

}

void AudioEngine::setSelectionStart( size_t waveIdx, size_t start )

{

    mPGranularNodes[waveIdx]->setSelectionStart( start );

}

void AudioEngine::setGrainDurationCoeff( size_t waveIdx, double coeff )

{

    mPGranularNodes[waveIdx]->setGrainsDurationCoeff( coeff );

}

void AudioEngine::setFilterCutoff( size_t waveIdx, double cutoff )

{

    mLowPassFilterNodes[waveIdx]->setCutoffFreq( cutoff );

}

// ------------------------------------------------------

// ----- methods for communication with main thread -----

// ------------------------------------------------------

size_t AudioEngine::getRecordWaveAvailable( size_t waveIdx )

{

    return mBufferRecorderNodes[waveIdx]->getRingBuffer().getAvailableRead();

}

bool AudioEngine::readRecordWave( size_t waveIdx, RecordWaveMsg* buffer, size_t count )

{

    return mBufferRecorderNodes[waveIdx]->getRingBuffer().read( buffer, count );

}

void AudioEngine::checkCursorTriggers( size_t waveIdx, std::vector<CursorTriggerMsg>& cursorTriggers )

{

    ci::audio::dsp::RingBufferT<CursorTriggerMsg> &ringBuffer = mCursorTriggerRingBufferPacks[waveIdx]->getBuffer();

    CursorTriggerMsg* ringBufferReadArray = mCursorTriggerRingBufferPacks[waveIdx]->getExchangeArray();

    size_t availableRead = ringBuffer.getAvailableRead();

    bool successfulRead = ringBuffer.read( ringBufferReadArray, availableRead );

    if ( successfulRead ){

        for ( size_t i = 0; i < availableRead; i++ ){

            cursorTriggers.push_back( ringBufferReadArray[i] );

        }

    }

}

const ci::audio::Buffer& AudioEngine::getAudioOutputBuffer( size_t waveIdx ) const

{

    return mOutputMonitorNodes[waveIdx]->getBuffer();

}